Kefir and yogurt are both fermented dairy foods packed with probiotics for gut health, but they differ in ways that matter. Yogurt uses two main bacteria (Lactobacillus bulgaricus, Streptococcus thermophilus) and has a thick, creamy texture. Kefir ferments with kefir grains—a mix of up to 61 bacteria and yeasts—making it fizzy, drinkable, and more probiotic-diverse. […]